For some perspective on just how bonkers Gilead's sales have gone since Sovaldi was approved in December 2013, last year the company's Q2 net product sales totaled $2.3 billion, or about $1.2 billion less than Sovaldi's sales alone this quarter.

In the company's earnings release, Gilead CEO John Martin said, "Since December's launch, Sovaldi has been prescribed for more than 80,000 patients in the U.S. and Europe, underscoring the medical community's recognition of the benefits of this product."

Gilead also boosted its full year product sales view substantially, saying it now sees full-year product sales of $21 to $23 billion compared to its prior outlook of $11.3 to $11.5 billion.

The company reiterated its earnings per share outlook of $0.63 to $0.66.

During the second quarter, Gilead generated $4.19 billion in operating cash flow, and the company used $1.2 billion to repurchase 15.2 million shares during the quarter.

Since the company's Q1 earnings report on April 22, shares of Gilead were up about 24%, and in pre-market trading the shares were up 1.1%.